Improvement in water-pressure cranes



-Fig. 1. Fig. 3 is a plan.

UNITED STATES PATENT OFFICE.

CHARLES H. MORGAN, OF WORCESTER, MASSACHUSETTS.

I IMPROVEMENT IN WATER-PRESSURE CRANES.

Specification forming part of Letters Patent No. 163,511, dated May 18,1875; application filed February 17, 1874.

To all whom it may concern:

Be it known that 1, CHARLES H. MORGAN,

of Worcester, in the county of Worcester and State of Massachusetts,have invented new and useful Improvements in Water-Pressure Cranes; andI do hereby declare that the fol lowing is a full, clear, and accuratedescription thereof, reference being had to the accompanying drawingsand to the letters of reference marked thereon.

The nature of my invention consists in organizing a water-pressure cranewith two passages through its step-spindle and step-casing, so thatindependent water engines on the crane for various purposes, such aslifting, traversing theload back and forth on the cranearm, andrevolving the crane, may take water under pressure from one passage andreturn their exhaust water to the other.

In my improved crane the lifting-engine is so arranged that when onlyhalf its full capacity is needed, only half the volume of water for eachfull stroke need be taken from the pressure-passage that would berequired for a complete stroke of full capacity; also, for rapid work,the piston may be forced down as well as up.

These ends are accomplished by means of connections opened and closed byvalves between the top and bottom of the cylinder; also between the topof the cylinder and the exhaust and pressure passages above mentioned,combined with what I call a differential piston. This piston consists ofa plunger whose area in cross-section may be half that of the cylinder,fastened at the bottom to a disk, which disk is fitted water-tight tothe inside of the cylinder by means of packing.

These improvements will be fully understood by reference to thefollowing specifications and accompanying drawings, in which Figure 1 isa side elevation. Fig. 2 is a vertical section at the plane of the paperin Fig. at is a cross.- section at j j, Fig. 2.

The same letters on the various figures refer to like parts.

a a is the step-casing, in which is the step 2, of hard wood, on whichthe crane revolves, and the annular spaces 1) and 1). Between theseannular spaces is a packing, f, confined in place bythe screws 6 epressing on the packing-ring d. Above the annular space b is a packing,f, confined in place between the packing-ring d and the gland 0. Openinginto the annular spaces b and b are the'supply and discharge pipes i andi and the passages h and h in the step'spindle gthe smaller passage, h,for water-pressure, and the larger one, h, for exhaust water. 70 and isare chambers in the passages h and 'h, with which, respectively, thepipes 0 and 0 connect the top of the cylinder q g, each pipe containinga valve, to and w. The ports a and p also open from these chambers intothe valve-chest Z. Other pipes may connect with the chambers 70 and 70,for the purpose of operating independent engines on the crane forsuchwork as traversing the load back and forth on the cranearm andrevolving the crane. The pipe .00, containing the valve to, connects thetop and bottom of the cylinder q q. Within the valvechest I is aslide-valve, m, to supply and exhaust the cylinder q q. Within thecylinder q q is the differential piston r 8, made up of the plunger 8,whose horizontal area may be one-half that of the cylinder q and thedisk 1", which is fastened to the bottom of the plunger, and fitted witha packing at t t to the inside of the cylinder q. The plunger 8 isalsopacked at a u, where it passes out of the cylinder-head o o. a ashow how the feet of the masts and struts of the crane are joined to thecylinder q, and so are made one with it.

Having now described the construction of the several parts of myimprovement in water-pressure cranes, I will proceed to describe theiroperation.

Having admitted the water under pressure to the supply-pipe z, andfilled the annular space b, the passage h, chamber 7c, and valvechest Zpress down the valve m till the port is open. The water rushes in,filling the cylinder q as the piston r s is forced upward.

Draw back the valve m to the position shown on Fig. 2, and. the pistonfalls as the water exhausts from the cylinder q through the ports p andp, chamber is, passage h, and annular space I) to the discharge-pipe 13.Should it be desired to hasten the exhaust, open the valve to, Fig. 3,in the pipe 0, and admit water from the pressure-chamber k to the top ofthe cyl i nder g, which will force the piston a" 8 down. If only half ofthe lifting capacity of the crane be needed, the valves w and w beingclosed, open the valve w in the pipe a 00, Fig. 1, connecting the topand bottom of the cylinder q. Open the valve m; the water will firstfill the top of the cylinder q through the pipe 00. Then the piston willbegin to rise with a force due to the difference of areas of the top andbottom of the piston, which, in this case, is onehalf. The water in thetop of the cylinder q will be forced to return through the pipe as a:and mingle with the incoming feed-water. When the valve m is againreturned to the position shown in Fig.2 the piston will begin todescend, and half the water in the cylinder below the piston 1" s willbe drawn back through the pipe as m to the'top of the cylinder by thevacuum created by the falling pis ton. The remaining half of the exhaustwater will pass off through the valve m to the discharge-pipe 6. Openingagain the valve 4%, the piston r s will at once begin to rise, as thepipe 00 0c and top of the cylinder (1 are already full. The process ofemptying the top of the cylinder into the bottom and refilling the topfrom the bottom will continue with each stroke of the piston. It will beseen that by this process on y half of the cylinder volume is drawn fromthe pressure-passage h for each full stroke of the piston. For rapidwork, when only half the lifting capacity of the crane is needed, thevalves w and w being closed, admit the water-pressure to the top of thecylinder 1 through the valve win the pipe 0. Open the valve m and thepiston r s will begin to rise. The water from the top of the cylinderwill be forced back through the pipe 0 to the chamber 70, and willmingle with the ingoing water from the pressure-passage h. When thevalve m is returned to the position shown in Fig. 2, the water in thecylinder q will be rapidly expelled because of the pressure on the topof the piston through the pipe 0. In this process each stroke of thepiston discharges a full cylinder of Water from the feed-pipe, but theworking of the crane is much accelerated. It is obvious that the loadsare lifted by their attachment to the pistonrod 2.

Having set forth the nature, construction, and operation of myinvention, what I claim, and desire to secure by Letters Patent, is-

1. In combination with the stand-case a of I a water-pressure crane, andthe step-spindle g turning therein, the annular spaces b b and gland c,and interposed packing between them, and the pressure and dischargepassages h h, as and for the purpose described and represented.

2. In combination with the step-spindle g, and the vertical passages h hthrough it, the chambers 70 and k, ports a p p, and valve andvalve-chest m l, as and for the purpose described and represented.

3. In combination with the cylinder q, the differential piston 1" 8 andlifting piston-rod 2, as and for the purpose described and represented.

4. In combination with the water-chambers 7c and 7c, cylinder q, anddifierential piston r s, the connecting-pipes 0, 0, and ac, and valves20, w, and w", all as and for the purpose described and represented.

CHAS. H. MORGAN.

Witnesses:

J. HENRY HILL, 1). H. ANDREWS.

